Captive tooless fastener for securing an engine intake air filter and clamp assembly for air filter housing

ABSTRACT

An engine intake air filter with a captive tooless fastener for securing the engine intake air filter. The tooless fastener comprises a shaft and an associated body. The body has two arms oriented about 180° from one another. The shaft is threaded through a sealing washer and an aperture in an closed end cap of the air filter. The shaft expanded or a component secured to the shaft such that the shaft cannot be removed from the end cap. The body has a threaded inner diameter that mates with a threaded portion of a central shaft in an air filter housing. The arms of the body are rotated to screw the fastener and the shaft of the housing together. When tightened, the aperture is closed by the sealing washer. To remove the air filter, arms are rotated in the reverse direction and the fastener is unscrewed from the shaft of the housing. In this loosened position the shaft floats in the aperture. A person in the field can insert his or her fingers under the arms. The person in the field can pull on the arms and thus use the fastener as a handle for removing the air filter. Optionally, the air filter is utilized in an air filter housing that is secured using a latch clamp assembly.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to engine intake air filters. Morespecifically, it relates to a captured tooless fastener for securing theengine intake air filter in the air filter housing and a clamp assemblyfor closing the air filter housing.

2. Description of Related Art

Many types of vehicles use engine intake air filters. In severe orextreme conditions, it is necessary to routinely replace and/or cleanthe air filter which is accommodated in an air filter housing.

For example, the United States military M998, 1¼ ton truck, also knownas the HMMWV or Hummer, uses an engine intake air filter secured inplace by 5/16th inch hex head nut 106. Once, housing cover 112 isremoved hex head nut 106 securing the air filter must be removed. Tocomplete the removal and/or installation of air filter 100, a wrench ofthe correct size must be used to loosen and tighten hex head nut 106. Inthe field, there is a risk that the wrench will be lost, misplaced, ordamaged. If the correct wrench is not available, necessary maintenancecannot be performed and in severe conditions, this can make the vehicleinteroperable.

Once removed nut 106 and coordinating sealing washer are removed, theybecome loose parts. If either part is lost or misplaced air filter 100cannot be properly reinstalled. If there is no replacement nut 106 andwasher, air filter 100 cannot be installed the vehicle is inoperable.

As shown in FIGS. 1 and 3 a, once the hex head nut 106 has been removeda ring 102 on the closed end cap 104 of air filter 100 is pulled toremove air filter 100 from housing 110. Ring 102 is a separate piecesecured to closed end cap 104. Because ring 102 is a separate piece fromclosed end cap 104, there is the risk that ring 102 could separate fromclosed end cap 104 due to careless manufacturing, failed spot welds,excessive force and/or extreme conditions. If ring 102 and closed endcap separate 104, there is no simple way to remove air filter 100.

When an air filter is being installed, there is a risk that the nut willbe over torqued using the wrench. This can damage a threaded shaft inthe housing that secures the air filter in position. If the threadedshaft is ruined the air filter cannot be replaced and the vehicle isinoperable.

Often people in the field have heavy gloves when replacing the airfilter. For example, in some military and industrial situations, thegloves may be hazmat gloves which may not be removed without seriousconsequences. In other situations, flame retardant or other protectivegloves may be needed. The gloves are clumsy and increase the risk thatthe nut and/or washer will be dropped and lost.

There is a need for an air filter that can be easily installed andremoved in the field without tools. There is a need for an air filterthan can be replaced without the risk of over torquing the nut. There isa need for an air filter which can be replaced without the risk oflosing an essential component. There is also a need for an air filterhousing which can be opened and secured without tools and without therisk of losing a component.

SUMMARY OF THE INVENTION

The inventive engine intake air filter includes a captive toolessfastener for securing the engine intake air filter. The tooless fastenercomprises a shaft and an associated body. The body has two arms orientedabout 180° from one another. The shaft is threaded through a sealingwasher and an aperture in an closed end cap of the air filter. The shaftexpanded or a component secured to the shaft such that the shaft cannotbe removed from the end cap. The body has a threaded inner diameter thatmates with a threaded portion of a central shaft in an air filterhousing. The arms of the body are rotated to screw the fastener and theshaft of the housing together. When tightened, the aperture is closed bythe sealing washer. To remove the air filter, arms are rotated in thereverse direction and the fastener is unscrewed from the shaft of thehousing. In this loosened position the shaft floats in the aperture. Aperson in the field can insert his or her fingers under the arms. Theperson in the field can pull on the arms and thus use the fastener as ahandle for removing the air filter.

Optionally, the air filter is utilized in an air filter housing that issecured using a latch clamp assembly.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a prior art air filter with a closed end cap.

FIGS. 2 a-2 b is an air filter housing and a cover with a prior artclosure.

FIG. 3 a is a prior art closed end cap of an air filter.

FIGS. 3 b and 3 c are a prior art hex nut for connecting the prior artclosed end air filter to an air filter housing.

FIG. 4 a is a cross section of the closed end cap of the air filter whenthe fastener is in a loose position.

FIG. 4 b is a cross section of the closed end cap of the air filter whenthe fastener is in a secured position.

FIG. 5 a is a top view of the tooless fastener

FIG. 5 b is a first cross section of a first tooless fastener along lineB-B of FIG. 5 a.

FIG. 5 c is a second cross section of the tooless fastener 90° alongline C-C of FIG. 5 a.

FIG. 5 d is an enlarged view of a portion of FIG. 6 a.

FIG. 6 a is a top view of the closed end cap of the air filter with atooless fastener.

FIG. 6 b is a cross section of the closed end cap of the air filteralong line B-B of FIG. 6 a.

FIG. 7 a is a top view of the alternative tooless fastener

FIG. 7 b is a first cross section of the alternative tooless fasteneralong line B-B of FIG. 7 a.

FIG. 7 c is a second cross section of the alternative tooless fasteneralong line C-C of FIG. 7 a.

FIG. 7 d is an enlarged view of a portion of FIG. 7 a.

FIG. 8 a is a top view of the closed end cap of the air filter with thetooless fastener.

FIG. 8 b is a cross section along line B-B of the closed end cap of theair filter of FIG. 8 a with the fastener in the loose position.

FIG. 8 c is a cross section along line B-B of the closed end cap of theair filter of FIG. 8 a with the fastener in the secured position.

FIG. 9 is a cross section of the shaft of the captive tooless fastenerand the closed end cap.

FIG. 10 a is a top view of an alternative closed end plate with acaptive fastener.

FIG. 10 b is a cross sectional view of an air filter along line B-B ofFIG. 11 a.

FIG. 11 a is a top view of a captured latch clamp assembly for a filterhousing in a closed position.

FIG. 11 b is a side view of the latch clamp assembly of FIG. 11 a.

FIG. 11 c is a top view of the band of the latch clamp assembly.

FIG. 11 d is a cross section of the band.

DETAILED DESCRIPTION OF THE INVENTION

An air filter assembly has a cylinder of pleated filter media 12, anexterior wire screen cylinder 14 surrounding the pleated filter media 12and an interior wire screen cylinder 15 on an interior of the pleadedfilter media 12. The wire screen cylinders 14 protect the pleated filtermedia 12, and provide rigidity and durability to the filter. The filterfurther comprises a first end with an open end cap 16 and a second endwith a closed end cap 18. Open end cap 16 is an annular ring having alip. The annular ring is sized such that a first end of the pleadedfilter media 12 and first end of wire screens fit the annular ring. Thesecond end cap has an annular lip 66. Annular lip 66 of closed end cap18 is sized such that the outer screen and pleaded filter media fit inthe inner diameter of lip 66. In manufacturing, heat curable adhesive isplaced between the end caps and the filter media. One end cap is appliedat a time using the heat curable adhesive. After application of theadhesive, the filter standing on an end cap is placed on a heatedsurface to heat cure the adhesive. The processes is repeated for theother end cap.

The air filter assembly is adapted to be accommodated in an air filterhousing 110. A threaded shaft in the housing cavity mates with captivetooless fastener 20 of closed end cap 18 to secure air filter in housing110. Tooless fastener 20 also acts as a handle for removal of the airfilter from housing 110.

Tooless fastener comprises a central shaft 22 extending from a body 24.A cylindrical cavity 26 extends through shaft 22 and body 24.Cylindrical cavity 26 comprises a first portion 26 a having a firstdiameter, a second portion 26 b having a second diameter, a thirdportion 26 c have a third diameter and a threaded body portion 26 d.Body portion 26 d may have a conical shape. Body portion 26 d hasthreads to mate with threads on threaded shaft of the housing 110. Anannular rib 28 extends outward at distal end 50 of shaft 22. An innerperipheral edge of annular rib 28 has a bevel 30.

In a second embodiment of the fastener, cylindrical cavity 26 comprisesa first portion 26 a having a first diameter and a second portion 26 bhaving a second diameter and a threaded body portion 26 d.

Length L of central shaft 22 may be adjusted depending on the desiredutilization. If the person in the field is likely to be wearing hazmatgloves or other gloves, it is desirable to have a longer shaft 22 suchthat gloved finger can more easily be inserted under arms 34 when usingthe fastener as a handle.

Body 24 comprises a central hub 32 with two arms 34 extending from hub32. Central hub 32 preferably comprises a truncated cone orfrustoconical outer surface 36 and substantially planar upper 38 andlower 40 surfaces. Each arm 34 is preferably opposed at a 180° angle tothe other. Arms 34 preferably have depressions 42. Depressions 42 makeit easier for a user to grip arms 34 when screwing or unscrewing thefastener to central shaft of housing 110. Arms 34 preferably have acontoured lower surface 44. Contoured lower surface 44 makes it easierfor a user to pull on the fastener to remove the air filter from housing110.

Sealing washer 48 is inserted over shaft 22. Shaft 22 of toolessfastener is then inserted through central aperture 52 in closed end cap18. Distal end 50 of shaft 22 is expanded outward to a diameter greaterthan the diameter of central aperture 52. Sealing washer 48 may use anyknow method to seal aperture 52. For example, sealing washer 48 maycomprise a metal washer with a layer of neoprene 54. The toolessfastener is oriented such that body 24 and sealing washer 48 are on anupper side of the closed end cap 18 and the expanded distal end 50 is onan under side of closed end cap 18. The fastener is secured to closedend cap 18. Preferably, distal end 50 of center shaft 22 is expandedoutward. Optionally, a separate piece can be secured on distal end 50 ofshaft 22. For example a nut could be welded to the end of shaft 22,thereby capturing it. However, this method is not preferred as itrequires additional parts and there is the risk the separate elementsuch as the nut could become separated from the fastener through roughuse or careless assembly.

Closed end cap 18 of the air filter is a plate 60 having a contouredupper 62 and lower 64 surfaces and an annular lip 66. Closed end cap 18has an annular planar surface 68. Closed end cap 18 is heated at annularplanar surface 68 to cure the adhesive used to secure the pleated filtermedia 12 to closed end cap 18. Closed end cap 18 has an annulardepression 70 centered on the plate 60. Central aperture 52 is locatedat the center of annular depression 70. Annular depression 70 preferablycomprises a first flat portion 72, a conical portion 74, and a secondflat portion 76.

When the fastening device is secured to the end plate 18, the body 24must not extend beyond the annular planar upper surface 68 of end cap18. If it extends beyond the planar surface 68, it becomes difficult toensure even curing of the adhesive. In addition, if the fastening deviceextends beyond the planar surface 68 when the air filter is secured in afilter housing 110, the housing cover 112 may not fit properly.

When the air filter is inserted in the housing 110, the central shaft ofthe housing 110 mates with the cylindrical cavity 26 in the shaft of thefastening device. As arms 34 are rotated, the fastening device screwsdown on the shaft in the housing 110 securing the air filter in thehousing 110 and compressing sealing washer 48 around aperture 52. Thethreads are preferably sized such that an average person can easily handtighten the fastener to tightness without the danger of over-torquingthat is common when using a wrench.

When the air filter is to be removed, arms 34 are used to unscrew thefastener from the central shaft of housing 110. The person in the fieldcan than insert a finger under each arm 34 and use the fastener as ahandle to pull the air filter from the housing 110.

Optionally, the air filter is utilized in an air filter housing that issecured using a latch clamp assembly 216. The latch clamp assembly 216comprises a clamping band 210 and a lever-type band tightening closuremechanism 216. Clamping band 210 is adapted to fit over an open end ofthe housing chamber and an outer diameter of the housing cover. Band 210has a divide 214 with a first end on one side of the divide 214 and asecond end on the other side of the divide 214.

Lever type band tightening closure mechanism 216 spans the divide 214and closes the band 210 when the lever 218 is closed. Lever type bandclosure mechanism comprises a first portion 220 having a first foot 222,a frame 224, and a lever 218, said lever 218 pivotally attached to theframe 224, a second portion 226 comprising a second foot 228, a hexflextop locknut 230 and a pin 232 connecting the first and secondportions 220, 228. The first foot 222 is connected to a first end of theband 210 and the second foot 228 is connected to a second end of theband 210. As the lever 218 is pushed down the pin 232 is pulled towardthe first side, thus pulling the second end of the band 210 toward thefirst end of the band 210 and closing divide 214. When the lever 218 isreleased, the pin 232 is pushed toward the second side and the secondend of the band 210 moves away from the first end, thus opening divide214. Band 210 and lever type band tightening closure mechanism arepreferably made of stainless steel.

1. An air filter comprising: a cylinder of a filter media; a first endcap on a first end of the cylinder, said first end cap comprises anannular ring having an outer diameter approximately the same as theouter diameter of the cylinder of filter media and an inner diameterapproximately equal to the inner diameter of the cylinder of filtermedia; a second end cap on a second end of the cylinder, said second endcap comprises a plate having an outer diameter approximately the same asthe outer diameter of the cylinder of filter media, an aperture in saidplate and a fastener in said aperture.
 2. The air filter of claim 1wherein the fastener is retained in a captured position in saidaperture.
 3. The air filter of claim 2 wherein the fastener comprises ahead, a shaft and a locking element, and said head and said lockingelement are larger than said aperture.
 4. The air filter of claim 4wherein the head, shaft and locking element are a unitary element. 5.The air filter of claim 4 wherein the shaft is a central shaft extendingfrom the head, a threaded cavity extends through the shaft, the lockingelement is an expanded portion of the end portion of the shaft, saidthreaded cavity adapted to mate with a threaded shaft in an air filterhousing.
 6. The air filter of claim 1 further comprising a pull ring onthe second end cap.
 7. The air filter of claim 3 further comprising awasher on the shaft of the fastener between the aperture and the head.8. The air filter of claim 3 wherein the locking element is a separateelement from the shaft.
 9. The air filter of claim 8 wherein the lockingelement is a nut.
 10. The air filter of claim 5 wherein the headcomprises a central hub and at least one arm extending from said hub.11. The air filter of claim 5 wherein the plate comprises a annular lipon an outer diameter, an annular flat surface and a central depression,said depression has a depth that is at least as deep as the a height ofsaid head.
 12. The air filter of claim 11 wherein the depth of thedepression is at least as deep as the height of the head and a washer onthe shaft of the fastener.
 13. The air filter of claim 5 wherein thewasher seals the aperture when the fastener is in a locked position. 14.The air filter of claim 10 wherein the at least one arm has at least oneof a contoured lower surface, a gripping surface.
 15. The air filter ofclaim 10 wherein the shaft has a length adapted such that a finger canbe placed under the at least one arm when the fastener is in an openposition.
 16. The air filter of claim 10 wherein the threads are sizedsuch that an average person can hand tighten the fastener to a centralshaft in an air filter housing.
 17. The air filter of claim 16 furthercomprising an inner cylinder and an outer cylinder on an inner and anouter surface of the filter media, adhesive securing the first end capand the second end cap to the filter media.
 18. The air filter of claim10 wherein the depression comprises a first flat portion, a conicalportion, and a second flat portion.
 19. The air filter of claim 11wherein the head comprises a truncated conical outer surface andsubstantially planar upper and lower surfaces.
 20. The air filter ofclaim 5 wherein the air filter is secured to a central shaft of an airfilter housing, said air filter housing comprising an open chamber and acover for closing said chamber, said cover is secured to said chamber bya band closed by a lever tightening mechanism.